Quick drying road marking composition and method

ABSTRACT

A road marking composition which may be applied to the roadway and used immediately after deposition by traffic which includes particular proportions of specific binders, pigments and solvents of a particular range of pigment volume concentration and solids content.

United States Patent 1 de Vries QUICK DRYING ROAD MARKING COMPOSITIONAND METHOD [75] Inventor: Edward R. de Vries, Lebanon, NJ.

[73] Assignee: Prismo Universal Corporation,

Rockville, Md.

[22] Filed: June 28, 1974 [21] Appl. No.: 484,315

Related US. Patent Documents Reissue of:

[64] Patent No.: 3,474,057

Issued: Oct. 21, 1969 Appl. No.: 606,023 Filed: Dec. 30, 1966 US.Applications:

[63] Continuation-in-part of Ser. No. 262,233, March 1, 1963, abandoned,which is a continuation-in-part of Ser. No. 231,283, Oct. 17, 1962,abandoned.

[52] US. Cl. 260/22 CB; 117/161 K; 260/312 X; 260/328 R; 260/336 UB;260/336 R;

[51] Int. Cl. C09D 3/64; C09D 3/66 [58] Field of Search 260/22 CB, DIG.38; 404/12-14; 117/105.1

[56] References Cited UNITED STATES PATENTS 2,268,537 12/1941 Shuger404/14 1 Reissued Aug. 26, 1975 OTHER PUBLICATIONS Paint IndustryTechnical Yearbook and Materials Manual, 1959, Vol. 4, published byHeckel Publishing Co., Philadelphia, Pa, pp. 212-223.

Primary Examiner-R0nald W. Griffin Attorney, Agent, or FirmCushman,Darby & Cushman 57 ABSTRACT A road marking composition which may beapplied to the roadway and used immediately after deposition by trafficwhich includes particular proportions of specific binders, pigments andsolvents of a particular range of pigment volume concentration andsolids content.

11 Claims, No Drawings QUICK DRYING ROAD MARKING COMPOSITION AND METHODMatter enclosed in heavy brackets 1 appears in the original patent butforms no part of this reissue specification; matter printed in italicsindicates the additions made by reissue.

The present application is a continuation-in-part of applicantsapplication Ser. No. 262,233, now abandoned, filed Mar. 1, 1963, andentitled, Reflective Marker, which was a continuation-in-part ofapplication Ser. No. 231,283 filed Oct. 17, 1962, now abandoned.

The present invention relates to reflective markings and moreparticularly to a reflective highway marker and composition therefor,which shows little or no deformation or smearing of the line by passingvehicles immediately after deposition.

Generally, reflective road markers in the form of traffic paints arecombinations of solvent, resinous binder and pigment supplied at aviscosity which is suitable for spraying or brushing. These trafficmarkers become sufficiently set, to allow traffic to pass over themwithout deformation or smearing of the line, by evaporation of thesolvent alone and subsequent polymerization of the resinous binder byoxidative processes. Some traffic paints set sufficiently by evaporationof solvent only; however, these types use solutions of hard resinousbinders which require more solvent to be used to obtain the desiredviscosity. This greater solvent volume is often more slowly releasedfrom such resins. Both types of these'materials require from 15 to 60minutes before traffic can be safely allowed to run over the markings.This requires the placement of protective markers and later collectingthem. This not only seriously restricts traffic flow but addsconsiderably to the cost of such marking.

Many attempts have been made to reduce the time required before thefreshly applied markings could be opened to traffic. The most successfulof these involved heating the material to the neighborhood of 160 F.just before application. This allowed the use of less solvent in thebase material since the higher temperature had the effect of reducingthe viscosity as required for successful application. The lower solventcontent yielded a more rapid development of no smear characteristics;however, not so rapid as to obviate the use of the protective cones. Theminimum time for no smear achieved by this method was 3 to 5 minutes;however, this is achieved only under ideal conditions, i.e. warm, dryday and using thin films. At normal film thickness as required forreasonable durability (approximately mils wet), at least 5 minutes arerequired for track free conditions under ideal weather conditions bythis technique.

A further serious shortcoming of the above, traffic paints, regardlessof their composition, is their prolonged time to achieve track freecondition at night. This is important since areas which are heavilytravelled in daytime need to be marked at night to prevent disastroustraffic tie-ups. Protection of the line for long periods at night isdifficult and dangerous due to more limited visibility.

It is therefore an object of the present invention to provide a linemarking methodand composition which enables traffic to pass over thesprayed lines almost immediately after deposition without pick-up,deformation or smearing of the lines regardless of the weatherconditions with the single exception of wet surfaces.

It is a further object of the present invention to provide a hot sprayquick drying traffic paint.

It is yet another object to provide a composition which can be sprayedon the road in thicker layers and yet will be immediately dry to notrack regardless of the weather conditions with the single exception ofwet surfaces.

Other objects and the nature and advantages of the instant inventionwill be apparent from the following description.

It has now been found that traffic paints which meet the aboverequirements can be prepared by the use of specific ingredients for thesolvent, binder and pigments using relatively narrow critical limits ofthese materials to obtain the desired pigment volume concentration andsolids content. The resulting traffic paint when applied according tothe method of the present invention will achieve the desired objectives.

The compositions according to the present invention have the followingingredients:

Percent by weight Binders 12-22 Pigments 50-69.4 Solvents (low boiling)7-23 Solvents (higher boiling) 5-20 Pigment volume concentration 46-62Solids content -85 The preferred range of ingredients in thecompositions as can be verified by the examples in this application isas follows:

Percent by weight Binders 14.0-21.7 Pigments 50.8-69.4 Solvents (lowboiling) 7. l-l6.l Solvents (higher boiling) 8.2-l8.5 Pigment volumeconcentration 46.7-60.l Solids content 7 l .3-83.9

The resins which are suitable as binders in the composition arepreferably glycerol or other polyfunctional alcohol phthalic alkyds ofshort and medium oil length which have a polyfunctional alcoholphthalate resin content of 40-58% and an oil content of 60-42%. Whenusing medium oil length alkyds having a polyfunctional alcohol phthalateresin content up to 51.6%, the oils should be selected from a groupincluding linseed, tung, dehydrated castor and oiticica or soybean.Shorter oil lengths of over 51.6% glyceryl phthalate resin content canbe based wholly on soybean oil due to the lower oil content. When higherconcentrations of oil are present it has been found that soybean oil isnot sufficiently conjugated and as a result the composition does not dryquickly enough. The alkyds can be modified with up to 20% by weight ofcertain hydrocarbon resins or with phenol to make phenolated alkyds. Ithas also been found that a short oil epoxy ester resin having an acidnumber less than 2 is also suitable for use as a binder. Short oilurethane esters have also been found to be suitable and to dry in asimilar manner to the alkyds. Benzoic acid condensations withpolyfunctional alcohols can also be formulated to give suitable results;however, such systems are somewhat brittle. Styrene butadiene or vinyltoluene-butadiene copolymers represent a binder which dries by solventevaporation only which is useful in connection with this invention;however, it must be used without the chlorinated plasticizers normallyassociated with these resins since such plasticizers affect solventrelease properties adversely.

The solvents used are a combination of a low boiling and a higherboiling solvent. The lower boiling solvent or combination of solventshas its boiling range below the temperature at which the material is tobe sprayed. This solvent or solvent combination is prevented fromevaporating or boiling due to the pressure in the system. Upon releaseof the pressure at the spray orifice this solvent is largely flashed outin the form of vapor. This flashing out of the solvents results in (a)breaking up the material in the form of fine droplets due to the suddenboiling out of this solvent component, (b) cooling the remainingmaterial rapidly due to the loss of the heat of vaporization as well asthe heat absorbed by the expanding atomizing air, and (c) increasing theconsistency of the material to a consistency approaching a track freestate before it hits the surface due to the cooling effect and the lossof the low boiling, high solvency, solvent. The other important functionof this solvent or solvent combination is to reduce the viscosity 'ofthe resin-pigment combination so that it can be pumped from itscontainer with available equipment while maintaining its high solidscontent. The required characteristics of this part of the solvent in thecomposition are: (a) high solvency for the resins used and (b) boilingpoint(s) below the spraying temperature. Suitable solvents arecyclohexane, pentane, petroleum ether, iso-hexane, hexane, methylenechloride, chloroform, carbon tetrachloride, ethylene dichloride,trichloroethylene, acetone, methyl ethyl ketone, ethyl acetate,isopropyl acetate, benzene and the like. The preferred solvents arethose that are chlorinated because of their high or lack of flash point.Of these methylene chloride is the most satisfactory because of its lowtoxicity, low boiling point and rapid reduction of viscosity of mostresins.

The'second portion of the solvent or solvent combination has thefunction of providing sufficient tack and flow to the pigment resincombination after it reaches the road surface to (a) adhere to thesurface on which 'it is applied, (b) incorporate and bind to glassspheres which may be added to obtain night visibility, and (c) from asmooth continuous line. This solvent should also be such that it willevaporate from the line marker quickly. This is accomplished by using afair to poor solvent for the resin and one which has a preferred boilingrange between 200 F. and 300 F. A portion may have a boiling point ashigh as 400 F. if it is very poor solvent for the resin. For example, ifthe resin is a medium oil phthalic alkyd (47% glyceryl phthalate, 53%oil) the solvent should be a mixture of aliphatic hydrocarbons withinthe boiling range containing not more than aromatic hydrocarbons and akauri butanol value of less than 50. Shorter oil phthalic alkyds (57%glyceryl phthalate, 43% oil), epoxy esters and the like can be used witharomatic solvents within the boiling range, such as toluene or xylene,since such binders require higher K-B solvents for solution.

The third basic part of the composition, the pigmentation, is alsocritical with respect to the achievement of the objects of theinvention. This is particularly true with respect to the extenders orlow refractive index pigments. The pigments which are suitable fordeveloping the opacity and/or color to the marking material are the sameas those traditionally used in such markers, i.e. rutile and anatasetitanium dioxide, chrome yellow (lead chromate), carbon black, and thelike. The pigments used of this type should be free of any treatmentdesigned to improve the dispersion characteristics of the pigment sincesuch treatments were found to adversely affect the no track time incompositions of this invention. The composition of this inventionrequires that the major portion of the volume of the pigmentation be oneor a combination of ground silica, natural clay, calcined clay, andcalcium sulfate. Further, the silica must have at least 50% of itsparticles finer than 3 microns with at least of its particles within 5microns of size distribution. The natural and calcined clays should haveat least 50% of their particles finer than 5 microns. Calcium sulfatepigments should be at least 80% within a range of 0.4 to 0.8 microns.Generally, the most suitable pigments are those which are not stronglywetted by the binder and which have their average particle size in thevicinity of 1.5 microns. Pigments significantly finer than this havesuch high oil adsorption that they require such high binder and solventconcentrations that their no track time does not meet the objectives ofthis invention as the major pigment component. Coarser and more easilywet pigments also do not meet the requirements regardless of otherformulation variables. Other types of extender (low refractive index)pigments can be used in small quantities providing the above pigmentsrepresent at least 50% of the total volume of the pigment.Representatives of these other types are calcium carbonate (whiting),magnesium silicate (talc), mica, and the like.

These pigments contribute importantly to this invention in that they areof a size, shape and have surface characteristics such that when inclose proximity to each other they developed high dilatancy andmicroporosity. Thus, when deposited on the substrate with little solventremaining in the material, a passing wheel will impart a force whichcauses the apparent viscosity of the system to be extremely high.Further, its microporous structure allows the remaining solvent toescape rapidly. Calcined clays give the best results because theircinder-like particles tend to lock together when they are in closeproximity and under stress.

Each specific pigment combination has a corresponding optimum pigmentvolume concentration. Below this level the time for no trackingcharacteristics increases rapidly and above this optimum the durabilitycharacteristics shows rapid deterioration, loss of adhesion, inabilityto hold glass spheres used as retroreflective elements, and dirtpenetration into the film due to excessive porosity. The no track" timefor these systems is determined by casting a 15 mil wet film of thecomposition and testing by the method described in A.S.T.M. Designation71 1-55. A result of 6 minutes or less by this test will generally havea no track time of one minute or less when applied and compoundedaccording to the teachings of the invention. Examples of the variationof no track time with pigment volume concentration of some pigments witha fixed volume of hiding pigments in a representative binder asdescribed in the invention are given below:

These examples illustrate the characteristics of those pigments whichare suitable for use in this invention compared with those which areunsatisfactory.

The composition in accordance with the present invention is handled forapplication by first pumping the material directly from its containerinto a closed system maintained at a fluid pressure of 100 to 150 poundsper square inch. The material is passed through aheat exchanger andheated linesfThis increases its temperature to a range between 140 F. to250 F. The most practical temperature was found to be 160 1 :10 P. Theheated material is then released from a spray orifice and is furtherbroken up by auxiliary air pressure.

The preferred viscosity of the composition of this invention should beas high as practical. The higher the viscosity the higher the solids ofthe composition and the closer it is to its no track state. A practicallimitation of handling the composition in cold weather is viscosity. Theminimum viscosity found which would allow the desired results to beobtained is approximately 80 Krebs units.

The following specific examples of formulations in accordance with thisinvention are illustrative only and should not be construed as limitingthe scope of the invention.

Additives-Briers and additives This formulation yielded a white painthaving a pigment volume concentration of 58.3 and a solids content of80.1%.

This formulation yielded a yellow paint having a pigment volumeconcentration of 56.7 and a solids content of 79.4%.

EXAMPLE 3 Percent Material: by weight BinderGlycero1-pl1thalic alkyd(47% glyceryl phthalic alkyd (477: glyceryl phtha1ate-537c oil) (oil-%soya-257r Chinawood) l6. Pigments:

Carbon black (pigment grade 1 Ground silica (1.5 microns) 52.

Magnesium silicate (talc) 6 Solvents:

Aliphatic hydrocarbon (15% aromatic, lBP

250F., EP 285F., KB 40) 10.4

Methylene chloride Additives-Briers and additives This formulationyielded a black paint having a pigment volume concentration of 60.1 anda solids content of 77.4%.

EXAMPLE'4 Percent Material: by weight Binder-Glycerol phthalic alkyd(47% glyceryl phthalic alkyd (47% glyceryl phthalate-53% oil) 10%Chinawood-% soya) 18.0 Pigments:

Rutile titanium dioxide 10.4

Calcium sulfate (0.6 micron) 24.3

Natural clay 24.3

Magnesium silicate 3.5 Solvents:

Aliphatic hydrocarbon (157: aromatic, lBP

250F., EP 285F., KB 40) 10.5

Methylene chloride 8.4 Additives-Driers and additives 0- Thisformulation has a pigment volume concentration of 56.7% and a solidscontent of 81.1%.

EXAMPLE 5 Percent Material by weight Binder-Glycerol phthalic alkyd (47%glyceryl phthalic alkyd (47% glyceryl phthalate-537z oil) (10%Chinawood-90% soya) 18.0 Pigments:

Rutile titanium dioxide 10.4

Natural clay 48.6

Magnesium silicate 3.5 Solvents:

Aliphatic hydrocarbon (15% aromatic. IBP

250F.. EP 285F., KB 40) 10.5

This formulation has a pigment volume concentra- -Continued tion of52.5% and a sollds content of 77.0%.

Methylene chloride 8.4 Additives-Driers and additives 0.6 EXAMPLE 10 I Iv Thls formulat1on has a plgment volume concentrav Percent tion of 58.0%and a solids content of 81.1%. Material: by weight Binder-Glycerolphthalic alkyd (47% glyceryl EXAMPLE 6 phtha1ate-53% oil) Chinawood-90%soya) 1 18.6 10 Pigments:

Rutile titanium dioxide 1 1.9 Percent Natural clay 42.2 Material: byweight Magnesium silicate 4.0 Binder-Glycerol phthalic alkyd (47%glyceryl Solvents: phthalic alkyd (47% glyceryl phthalate-53% Aliphatichydrocarbon aromatic, IBP oil) (10% Chinawood-90% soya) 21.7 250F., EP285F., KB 40) 10.0 Pigments: l5 Methylene chloride 10.6

Rutile titanium dioxide 15.2 t es Calcined clay (1.5 microns) 35.6Coumaron-indene hydrocarbon resin modifier Solvents: (M P. 200-220F.,iodine value 230 heat re- Aliphatic hydrocarbon (15% aromatic, IBP P- 9-Acid 250F., EP 285F., KB 40) 15.7 Drlers and addmves 0.6 Methylenechloride 11.0 Additives Ducts and addmves This formulation has a pigmentvolume concentration of 55.0% and a solids content of 79.4%. Thlsformulation has a plgment volume concentration of 46.7% and a solidscontent of 73.3%. EXAMPLE l1 EXAMPLE 7 Percent Material: a by weightpercent Binder-Glycerol phthalic alkyd (47% glyceryl Material: by weightphthalate-53% oil) (10% Chinawood-90% Bindcr-Glycerol phthalic alkyd(47% glyceryl if phthalic alkyd 47% glyceryl phtha1ate-53% f Oil) 1;chinawood go% soya) 193 Rutlle tltanlum d1ox1de 12.3 Pigments. Naturalclay 43.5 Rutile titanium dioxide 13.8 Magneslum s'hcat a Solvents:

calcined day (15) microns) r Aliphatic hydrocarbon (15% aromatic. IBP

Solvents: A

Aliphatic hydrocarbon 15% aromatic, IBP g lf- EP 3 KB 49) 250F.. EP2ss1=., FB 14.2 f gj? Methylene chloride 10.0 3

Additives-Briers and additives 0.1 5 5 5 ggig ggggggggg g g- 3 activeSap No. 0-2 Acid No. 0-2) 4.3 This formulation has a pigment volumeconcentraand addltlves 07 tion of 51.6% and a solids content of 75.8%.

This formulation has a pigment volume concentra- EXAMPLE 3 40 tion of57.8 and a solids content of 82.0.

EXAMPLE 12 Percent Material: by weight Binder-Glycerol phthalic alkyd(47% glyceryl H Percent phthalic alkyd (47% glyceryl phthalate-53%Material. by weight 5 chmflwood-goq Soya) Binder-Glycerol phthalic alkyd(57% glyceryl f phlhalatc-43% Soya oil) 19.0

Rut1lc t1tan1um d1ox1de 13.8 Pigments: I S f y Rutile titanium dioxide10.9 oven 5: N t l l r Aliphatic hydrocarbon 15% aromatic, IBP Mzrlgsifnz silicate g 2501=., EP 285F., KB 40 .2 Solvents: Methylenechloride 10.0 Xylene 2 Additives-Driers and additives 0.7 MethyleneChloride. 4 Additives-Driers and additives 0.6

This formulation has a pigment volume concentra- 1 tion f and a SolidsContent f 75 3% This formulation has a pigment volume concentration of53.2 and a solids content of 72.7. EXAMPLE 9 EXAMPLE 13 PercentMaterial: y Weight Percent Binder-Glycerol phthalic alkyd (47% glyceryl60 Mat ri l; b eight phthalic alkyd (47% glyceryl phthaIate-53%Binder-Glycerol phthalic alkyd (50% glyceryl Oil) (10% Ch1nawood-90%soya) 20.0 phthalate-50% dehydrated castor oil) 18.5 Pigments: Pigments:

Rutile titanium dioxide 1 1.6 I Rutile titanium dioxide 10.7 Naturalclay 40.9 I Natural clay I 37.8 Magnesium silicate 3.9 Magnesiumsilicate 3 6 Solvents: Solvents: v

Aliphatic hydrocarbon (15% aromatic, IBP v r Aliphatic hydrocarbon (15%aromatic. IBP 250F., EP 285F., KB 40) 11.7 2SOF., EP 285F., KB 40) 18.5

Methylene chloride Methylene chloride 10.2 Additives-Driers andadditives 0.6 Additives-Dries and additives 0.7

This formulation'has a pigment volume concentration of 51.6 and a solidscontent of 71.3.

This formulation has a pigment volume concentration of 54.6 and a solidscontent of 71.3.

EXAMPLE 15 Percent Material: by weight Binder-Glycerol phthalic alkyd(50% glyceryl phthalate-507z DCO) (dehydrated castor oil) 18.5 Pigments:

Rutile titanium dioxide 10.7

Natural clay 37.8

Magnesium silicate 3.6 Solvents:

Aliphatic hydrocarbon (157c aromatic, IBP

250F., EP 285F, KB 40) 18.5

Methylene chloride 7 10.2 Additives-Driers and additives 0.7

This formulation has a pigment volume concentration of 54.6 and a solidscontent of 71.3.

EXAMPLE 16 Percent Material: by weight Binder-Glycerol phthalate alkyd(477: glyceryl phthalate-53% oil) Chinawood-907z soya) Pigments Rutiletitanium dioxide Natural clay Magnesium silicate Glass spheres (-45mesh) Solvents:

Aliphatic hydrocarbon aromatic. lBP 250F, EP 285F, KB 40) Methylenechloride Additives-Briers and additives This formulation has a pigmentvolume concentration of 52.4 and a solids content of 83.9.

This formulation has a pigment volume concentration of 59.4 and a solidscontent of 73.7.

EXAMPLE 18 Percent Material: by weight Binder-Glycerol phthalic alkyd(47% glyceryl phthalate-537c oil) (10% Chinawood-% soya) 20.9 PigmentsRutile titanium dioxide 10.9 I Calcium sulfate (0.6 microns) 25.3Calcined clay (1.5 microns) 24.1 Solvents:

Aliphatic hydrocarbon 15% aromatic, lBP 250F., EP 285F., KB 40) 11.3Methylene chloride 7.1 Additives'Driers and additives 0.4

This formulation has a pigment volume concentration of 48.1 and a solidscontent of 81.6.

. EXAMPLE 19 Percent Material: by weight Binder-Phenolated alkyd (40%phthalic anhy dried-4% soya oil) (MIL R-l5190A) 16.4 Pigments Rutiletitanium dioxide 8.9

Calcium sulfate (0.6 microns) 20.8

Ground silica 1.5 microns) 26.5

Magnesium silicate 3.3 Solvents:

Aliphatic hydrocarbon (15% aromatic, IBP

250F., EP 285F., KB 40) 16.4

Methylene chloride 7.3 Additives-Driers and additives This formulationhas a pigment volume concentration of 58.5 and a solids content of 76.3.

After the composition in accordance with the previous examples has beensprayed onto the roadway, glass beads can be immediately dropped ontothe paint while it is still tacky so that the beads become partiallyembedded in the paint and it yields a line that isimmediatelyretroreflective. The higher boiling solvent retards thesetting up of the paint until it has reached the road and the glassbeads have been dropped in.

Traffic can pass over the lines of the present invention within 1 to 2minutes of being sprayed without any smearing or deformation of thelines. This differs from the prior systems due to the fact that in theprior systems as long as even fairly small percentages of solvent areretained the consistency of the film deposited is not stiff enough tolet traffic pass over, even though the surface is dry to touch due toso-called skinning over. It is exactly the skinning over effect thattraps solvent in the film and prevents any further reduction in.dryingtime regardless of decreased solvent content and increased temperature.This is not true in the present invention which evaporates most solventbefore deposition and in which the binder has a high consistency duringdeposition. I

It will be obvious to those skilled in the art that various changes maybe made without departing from the scope of the invention and theinvention is not to be considered limited to what is described in thespecification.

What is claimed is:

l. A traffic line paint capable of being sprayed when heated comprisingby weight Percent Resin binder 12-22 -Continued Percent Pigments 50-69.4Low boilng solvents 7-23 Higher boiling solvents -20 Pigment volumeconcentration 46-62 Solids content 70-85 said resin binder beingselected from the group consisting of short and medium oil lengthglycerol or other polyfunctional alcohol phthalic alkyds having apolyfunctional alcohol phthalate resin content of 40-58% and an oilcontent of 60-42%, said low boiling solvents having a high solvency forthe resin binder and a boiling range below the temperature at which thepaint is sprayed, and said higher boiling solvents having a boilingrange between ZOO-400 F.

2. A traffic line paint according to claim 1 wherein the major portionof said pigments is selected from the group consisting of ground silica,natural clay, calcined clay and calcium sulfate having at least 50% oftheir particles finer than 5 microns.

3. A traffic line paint according to claim 2 wherein said low boilingsolvent is methylene chloride.

4. A traffic line paint according to claim 3 wherein said resin binderis a glycerol phthalic alkyd having a glyceryl phthalate resin contentof 40-58% and an oil content of 60-42%.

5. A traffic line paint according to claim 4 wherein said higher boilingsolvent is an aliphatic hydrocarbon, aromatic; IBP 250 F., EP 285 F. andKB 40.

6. A method of applying a traffic line marker which is almostimmediately dry upon deposition comprising pumping a traffic paint intoa closed system under a fluid pressure of about 100-150 lbs/sq. inch,said traffic paint containing a resin binder, pigments, a higher boilingsolvent, a pigment volume concentration from 46-62%, a solids content of70-85% and from 7-23% of a low boiling solvent therein having a highsolvency for the resin binder and a boiling range below the temperatureat which the paint is to be sprayed, heating said paint to a temperatureof about l40-250 F., releasing said heated paint through a sprayorifice, applying aux- Percent Resin binder 1.0-21.7 Pigments 50.8-69.4Low boiling solvents 7.1-16.I Higher boiling solvents 8.2-18.5 Pigmentvolume concentration 46.7-60.1 Solids Content 71.3-83.9,

10. A traffic line paint according to claim 1 wherein the proportions ofingredients are as follows:

Percent Resin binder 20.0 Pigments 56.4 Low boiling solvents 1 1.3Higher boiling solvents 1 1.7 Pigment volume concentration 52.5 Solidscontent 77 11. A traffic line paint in accordance with claim 10 havingthe following composition:

Percent Glycerol phthalic alkyd (47% glccryl phthalate -537c oil) (107:Chinawood-% soya) 20.0 Rutile titanium dioxide 1 1.6 Natural clay 40.9Magnesium silicate 3.9 Aliphatic hydrocarbon 15% aromatic, lBP 250 F. EP285F., KB 40) 11.7 Methylene chloride 1 1.3.

1. A TRAFFIC LINE PAINT CAPABLE OF BEING SPRAYED WHEN HEATED COMPRISING BY WEIGHT
 2. A traffic line paint according to claim 1 wherein the major portion of said pigments is selected from the group consisting of ground silica, natural clay, calcined clay and calcium sulfate having at least 50% of their particles finer than 5 microns.
 3. A traffic line paint according to claim 2 wherein said low boiling solvent is methylene chloride.
 4. A traffic line paint according to claim 3 wherein said resin binder is a glycerol phthalic alkyd having a glyceryl phthalate resin content of 40-58% and an oil content of 60-42%.
 5. A traffic line paint according to claim 4 wherein said higher boiling solvent is an aliphatic hydrocarbon, 15% aromatic, IBP 250* F., EP 285* F. and KB
 40. 6. A method of applying a traffic line marker which is almost immediately dry upon deposition comprising pumping a traffic paint into a closed system under a fluid pressure of about 100-150 lbs./sq. inch, said traffic paint containing a resin binder, pigments, a higher boiling solvent, a pigment volume concentration from 46-62%, a solids content of 70-85% and from 7-23% of a low boiling solvent therein having a high solvency for the resin binder and a boiling range below the temperature at which the paint is to be sprayed, heating said paint to a temperature of about 140-250* F., releasing said heated paint through a spray orifice, applying auxiliary air pressure to said sprayed material immediately after leaving said orifice, and directing said sprayed stream onto a roadway surface.
 7. A method according to claim 6 wherein reflectorizing glass spheres are applied onto said marker immediately after deposition onto said roadway surface.
 8. A method according to claim 6 wherein said traffic paint is in accordance with claim
 1. 9. A traffic line paint according to claim 1 wherein the proportions of the ingredients are as follows:
 10. A traffic line paint according to claim 1 wherein the proportions of ingredients are as follows:
 11. A traffic line paint in accordance with claim 10 having the following composition: 